This application claims priority of International application number PCT/DE00/00843, filed Mar. 15, 2000, which in turn claims priority to German patent application number 199 11 358.0, filed Mar. 15, 1999.
The invention relates to an automobile seat with a seat frame, a seat surface provided on the seat frame, and a backrest which is pivotally mounted on the seat frame and can be folded towards the seat surface.
Seats of this kind are used as front seats in automobiles so that by folding the backrest forwards it makes it easier for the passenger to climb into the back of the vehicle or to slide an object into the back of the vehicle. It becomes even easier to climb into the back of the vehicle, particularly in the case of two-door vehicles, if the seat can be pushed forwards after the backrest has been folded forward.
For this the automobile seat has the following features:
a longitudinal guide with which the seat frame can be moved in the longitudinal direction of the seat in order to adjust the longitudinal position of the seat;
a fixing device for locking the seat frame in a previously set seat longitudinal position;
an operating element for unlocking the fixing device so that the seat frame can be moved in the longitudinal direction of the seat;
a coupling mechanism for coupling the fixing device to the backrest which acts on the operating element and thereby unlocks the fixing device when the backrest is folded forwards towards the seat surface;
a memory device by means of which the seat frame during movement in the longitudinal direction of the seat can be stopped automatically in a predeterminable longitudinal seat position defined as the memory position, where a stop associated with the seat frame and movable in the longitudinal direction of the seat comes into engagement with a counter stop of the memory device;
regulating means for the memory device with which the memory position can be regulated in the longitudinal direction of the seat by adjusting the position of the counter stop;
a locking device for the memory device for locking a selected memory position; and
switching means with which the locking device can be unlocked in order to be able to regulate the memory position.
A seat of this kind offers on the one hand the possibility, after folding the backrest forwards towards the seat surface, of sliding the seat frame, and thus the entire vehicle seat, forwards in order to make it easier for a passenger to climb into the back (easy-entry function). Then at the same time the seat can be very easily moved back again into its original longitudinal position if this longitudinal position of the seat is stored as the memory position by means of the memory device which is provided for this purpose. In this case the seat frame is automatically stopped in the memory position as the seat is pushed back, with a stop associated with the seat frame interacting with a counter stop of the memory device.
In the case of a vehicle seat of this kind which is known from DE 42 01 829 A1 and which has a seat frame with a backrest which can be folded forwards, a longitudinal guide for regulating the longitudinal position of the seat, a fixing device associated with the longitudinal guide, and a coupling mechanism with which the fixing device can be unlocked when the backrest is folded forwards towards the seat surface, the fixing device can only be locked again after the seat has been moved with the backrest folded forwards, after the seat has been moved back into the original position which has been memorised by the memory device. This not only involves a reduction in operating comfort but can also result in a considerable risk of danger to a person seated on the seat if this person takes up their place on the seat before the seat has been moved completely back into its memory position, e.g. because luggage or packages behind the seat prevent the seat from moving back into the memory position. A person seated on a vehicle seat which has not been locked is exposed to a considerable risk of injury in the event of a crash.
From DE 196 47 447 A1, a vehicle seat is known having a fold-forward backrest, an easy-entry function with the backrest folded forward and memory function for relocating the original seat position which can also be locked outside of the memory position and can thus be brought into a safer useful position. With this seat, gearing is provided with which longitudinal movement of the vehicle seat can be converted into rotary movement of individual gear elements. The memory function is hereby provided by means of stops and spring elements which interact with the rotatable gear elements. This known vehicle seat has the drawback however that a comparatively high assembly expense is required in order to produce a sufficiently precise match between the different displaceable, swivelling and rotatable component parts which are provided to produce the combined easy-entry and memory functions.
The object of the invention is therefore to provide an automobile seat of the type mentioned at the beginning which has both a simple construction and a high functional reliability.
According to an embodiment of the invention, the coupling mechanism, which acts on the operating element of the fixing device and unlocks the fixing device when the backrest is folded forwards towards the seat surface, only acts on the operating element so long as the backrest is folded forwards. Thus, the seat frame can be locked at any time by locking the fixing device if the backrest is no longer folded forwards, thus, folded back again into its functioning position. In particular, when the backrest is folded up, the ability of the seat frame to be locked in an actual longitudinal position of the seat is independent of whether the relevant longitudinal position, at that time, of the seat corresponds to the memory position.
A solution according to an embodiment of the invention leads to an increase in operating comfort, since the variability is increased regarding the longitudinal positions of the seat which can be regulated and locked after implementing the easy-entry function. At the same time, the functional reliability is improved since the seat can also then be locked even if it is not located in the memory position so that no safety risk can arise as a result of an inadequately secured seat.
The seat frame includes all the constituent parts of the supporting seat structure which can be moved in the longitudinal direction of the seat, and also those constituent parts of the longitudinal guide of the seat, such as e.g. a seat rail (top rail) which is moved in the longitudinal direction when regulating the longitudinal position of the seat.
In an embodiment of the invention, locking means are provided which are coupled to the backrest and which, when the backrest is folded forwards, act on the switching means provided for unlocking the locking device of the memory device so that when the backrest is folded forwards, unlocking the locking device is prevented. Therefore, when the backrest is folded forwards, the locking device of the memory device is always locked so that no change can be made to the memory position.
The locking means can be coupled to the backrest, for example, through a push or pull means, more particularly in the form of a cable. However, a lever arrangement or other gearing can also be used for coupling. It is only necessary for the means which are used for coupling to be suitable for converting a swivel movement of the backrest into a movement of a locking element and to bring this into a position in which it blocks the unlocking of the locking device for the memory device.
The locking means can thereby be coupled to the backrest through the same coupling mechanism as the operating element which causes the unlocking of the fixing device of the seat longitudinal guide when the backrest is folded forwards.
In order to bring a locking element of the locking means into engagement with the switching means it can be proposed, for example, that when folding the backrest forwards, the locking element is moved in the longitudinal direction of the seat. As an alternative, a swivel movement of the locking element when folding the backrest forwards, or any other type of movement, can be provided.
The locking element has, for example, a stop which, when the backrest is folded forwards, comes into active connection with the switching means in order to block any unlocking of the locking device of the memory device. Alternatively, the locking element can also be connected to the switching means and when the backrest is folded forwards acts on the switching means so that unlocking of the locking device is hereby prevented.
The switching means which are provided for unlocking the locking device of the memory device can be formed, for example, by a switching lever or by a switching spring wherein the latter is swivelled for unlocking the locking device and the latter is formed for the same purpose. A displaceable switching means can likewise be used.
The switching means are preferably mounted on the seat frame and are arranged so that they can only then act on the locking device for the purpose of unlocking the locking device when the seat frame is located in the memory position. This means that a change in the memory position, which does indeed presuppose an unlocking of the locking device, can only then be undertaken when the seat frame is located in the actual memory position.
In an advantageous further development the switching means are elastically pretensioned in the direction of a first switching position and can be switched against the action of this pretension into a second switching position where in one of the two switching positions the locking device is locked and in the other switching position the locking device is unlocked.
In one embodiment of the invention, the switching means are coupled to the fixing device of the longitudinal guide of the seat when the seat frame is located in the memory position and can therefore be switched at the same time during operation of the fixing device.
According to one variation during unlocking of the fixing device, the switching means are switched so that the locking device is unlocked. This means that during unlocking of the fixing device of the seat longitudinal guide in the memory position, the locking device of the memory device is also unlocked at the same time so that a new memory position can be set. However, through the aforementioned locking means it can also be ensured that this is only then possible when the backrest is not located in the forward folded position. For when moving the seat for the purpose of easier entry into the vehicle there should indeed, as a rule, be no change to the memory position.
According to another variation when locking the fixing device for the longitudinal seat guide, the switching means are switched so that the locking device for the memory device is unlocked. With this vaiation the regulating means for the memory device provided for changing the memory position are thus automatically switched free during locking of the fixing device for the seat longitudinal guide. Then the fixing device is again unlocked in order to be able to move the seat frame in the longitudinal direction of the seat it is also possible for a correction to the memory position to take place at the same time. Obviously, by means of the aforementioned locking means, it can also be brought about that the free switching of the regulating means for the memory device is only possible when the backrest is not folded forward.
It can furthermore be proposed that, in the memory position of the seat frame, when the backrest is not folded forward and when the locking device for the memory device is unlocked, the switching means are supported so that when the fixing device is unlocked the switching means are not shifted. For this, the switching means can be supported, for example, on a support surface or can also be pretensioned into a certain position by means of an elastic element.
In order to prevent the regulating means of the memory device automatically being switched free when approaching the memory position, with the result that during subsequent adjustment of the longitudinal position of the seat the memory position would also be changed at the same time, it can be proposed that the switching means on approaching the memory position with the backrest not folded forward are at first deactivated and an immediate unlocking of the locking device for the memory device is thereby blocked. During subsequent locking of the fixing device, the switching means can then be activated so that they can again act on the locking device for the memory device for the purpose of unlocking same. This can be carried out in particular if the locking device is automatically unlocked during subsequent unlocking of the fixing device.
In order to deactivate the switching means on approaching the memory position with the backrest not folded forward, it can be proposed that the switching means are associated with a guide face of the memory device and that this guide face is designed so that the switching means on approaching the memory position are guided along the guide face and can thereby not act on the locking device. With subsequent locking of the fixing device the switching means can then be automatically activated so that they are again lifted away from the guide face. With subsequent renewed unlocking of the fixing device (with the backrest not folded forwards) the switching means can again act on the locking device of the memory device in order to freely switch the regulating means.
In another embodiment, the switching means are associated with a stop face of the memory device which is arranged so that on approaching the memory position with the backrest not folded forwards it acts on the switching means in order to prevent unlocking of the locking device through the switching means. With subsequent locking of the fixing device, the switching means are thereby activated so that they are again lifted from the stop face.
In another embodiment of the invention, the locking device of the memory device is elastically pretensioned towards its locked position and the switching means can act in the memory position when the backrest is not folded forwards on the locking device so that this is unlocked against the elastic pretension.
The locking device for the memory device preferably consists of a locking unit which can be displaced together with the counter stop of the memory device in the longitudinal direction of the seat, and a detent device which is associated with the locking unit and which has detent positions set in succession in the longitudinal direction of the seat at which the locking unit can be locked relative to the detent device in order to fix the memory position.
The locking unit can comprise, for example, a swivel mounted locking pawl which has a detent element, which can engage in the detent positions of the detent device, whereby the locking pawl is provided with an operating section on which the switching means can act in order that the detent element can engage in the detent device or disengage therefrom.
When setting the longitudinal position of the seat, in order that the memory position can be adapted at the same time, the memory device has a follower which can be brought into engagement with the seat frame so that the counter stop and the locking unit of the memory device can be moved together with the seat frame in the longitudinal direction of the seat. The follower is, for this purpose, associated with an engagement area of the seat frame, and the follower can be brought into engagement with the engagement area, for example, by swivelling the follower and engagement area relative to each other.
The follower and the engagement area can preferably only be brought into engagement with each other when the seat frame is located in the memory position and when the locking device for the memory device is unlocked. The follower itself can be mounted, for example, on the locking pawl.
The regulating means with which the memory position can be regulated can advantageously be formed by a glide which is mounted movable in the longitudinal direction of the seat and on which the locking unit and counter stop of the memory device are mounted.
According to a further variation of the invention, it is proposed that at least one elastically pretensioned slider is mounted movable on the memory device or on the seat frame, and in the memory position is supported against pretension on a stop element of the seat frame or memory device, and during displacement of the seat frame is moved out from the memory position (with the backrest folded forward) as a result of the said pretension into such a position that it prevents unlocking of the locking unit. It is hereby ensured that, outside of the memory position, it is not possible for the locking unit of the memory device to become unlocked.
According to a variation the locking unit itself hereby has an elastically pretensioned movably mounted slider which, in the memory position, is supported against pretension on a stop element of the seat frame and which during displacement of the seat frame is moved out of the memory position as a result of the pretension into such a position that it prevents unlocking of the locking unit outside of the memory position. Thus, the slider can be moved, for example, during displacement of the seat frame out from the memory position as a result of the pretension into such a position that it engages on the locking pawl of the locking unit and thereby prevents the locking pawl from becoming unlocked.
According to another or complimentary variation the seat frame has an elastically pretensioned movably mounted slider which is supported in the memory position of the seat frame against the pretension on a stop element of the memory device and which, during displacement of the seat frame, is moved out from the memory position with the backrest folded forward as a result of the pretension into such a position that it blocks the switching means from acting on the locking device which would lead to unlocking of the locking device. It is thereby further ensured that the position of the slider is not influenced when later folding the backrest back up outside of the memory position from the forward folded position. It is hereby reached that folding the backrest back up outside of the memory position does not lead to the regulating means for the memory device being released which would result in a change to the memory position.
If the seat frame is then moved back again into the memory position, then the slider interacts with a stop element so that the slider, on reaching the memory position, is moved against the pretension and thereby no longer blocks the unlocking of the locking device for the memory device.
If in this case the switching means are elastically pretensioned towards a switching position in which they engender unlocking of the locking device, then on reaching the memory position, unlocking of the locking device automatically takes place so that a new adjustment of the memory position is possible.
In another embodiment, it is hereby possible to design the spring by means of which the slider is pretensioned, so that the slider can only be moved against the pretension by applying comparatively larger forces. The slider is, in this case, only then moved into a position in which it no longer blocks unlocking of the locking device when the seat is moved by the user with a sufficiently large force into the memory position. Re-programming of the memory position can then take place.
If, however, the seat is only moved into the memory position with a comparatively lower force then the pretension acting on the slider cannot be overcome so that the slider blocks unlocking of the locking device.